Figure 2: Design and images of the FMi-OOC model.

A) Schematic illustration of the FMi-OOC highlighting the four cell culture chambers connected by arrays of 24 microchannels.

B) Cross-sectional view of the cell culture chambers showing the chamber height (250 μm), individual chamber diameters (mimicking in utero thickness), and the interconnecting microchannel lengths.

C) Image of the microfabricated FMi-OOC where each cell culture chamber were filled with different color dye for easy visualization, namely the choriodecidua interface (decidua – green; chorion – yellow) and the amniochorionic interface (chorion – yellow; amnion – AMC [purple] and AEC [blue]).

D) Design of an on-chip media reservoir layer that was aligned and placed on top of the cell loading inlets and outlets (seen in image C) of the main cell culture layer, both to provide sufficient media for culture and also to control the diffusion between the cell culture layer through controlling the hydrostatic pressure between the chambers by filling the reservoirs to different height. I addition, localized chemical treatments can be performed as well as effluents collected from each culture chamber through these reservoirs. The center decidua layer has one reservoir, the chorion and AMC have two each, while the AEC chamber has four.

E) The FMi-OOC device with the integrated media reservoir filled with color dye in each of the corresponding cell culture layers.